Peripherial Nervous System Flashcards
How many pairs of cranial nerves?
12
Which 2 cranial nerves are entirely sensory?
1 and 2
What cranial nerves are entirely motor?
3, 4 & 6
True/False: several cranial nerves are autonomic
True
How many pairs of spinal nerves?
31
All spinal nerves except which one are both motor/sensory?
C1
What side of the spine do sensory nerves run?
Dorsal
What side of spine do motor nerves run?
Ventral
What is a map of somatosensory input from specific areas of skin that corresponds with specific nerves called?
Dermatome map
Where is spinal gray matter?
Center of spinal cord
What does spinal gray matter contain?
Cell bodies of nerve cells
What matter contains high fat content and myelination of fibers?
White matter
What fibers run up the white matter to the brain?
Afferent (sensory)
What fibers run down the white matter from the brain?
Efferent (motor)
What is contained in the Lateral Horn of gray matter?
Cell bodies of autonomic nerves
What part activates a contraction when a rapid stretch to the muscle happens?
Muscle spindle
What branch of the PNS controls smooth and cardiac muscle and glands?
Autonomic
What are 2 parts of autonomic nervous system?
1) sympathetic
2) parasympathetic
What part of autonomic nervous system controls fight/flight?
Sympathetic
What part of autonomic nervous system controls rest/digest?
Parasympathetic
For the most part, are autonomic nerves afferent or efferent?
Mostly efferent but afferent nerves can get signals from viscera
What is the usual organization of the autonomic nervous system?
2 cells + 2 synapses
Where are pre ganglionic cell bodies of sympathetic nervous system located?
Lateral horn of spinal cord between T1-L3
Where are pre ganglionic cell bodies of the Parasympathetic nervous system located?
1) Midbrain
2) medulla
3) lateral horn T12-L1
What cranial nerves are part of parasympathetic nervous system whose cell bodies sit in the midbrain and medulla?
3, 7, 9 & 10
Where do parasympathetic nerves in T12-L1 exit the vertebral canal?
S2-S4
Where are post ganglionic cells of the sympathetic nervous system located?
1) parabvertebral ganglia
2) prevertebral ganglia
Where is the pre ganglionic neuron located?
In CNS
Where is post ganglion neuron located?
In a peripheral ganglion outside the CNS
What runs parallel to spinal cord on both sides of vertebral column?
Sympathetic Chain Ganglion
Where does 1st synapse of preganglion cells occur?
Sympathetic chain ganglion
What is another word for the sympathetic chain ganglion?
Para vertebral ganglia
What 2 cell bodies make their 1st synapse in the prevertebral ganglia?
1) celiac
2) hypogastric
What arm of sympathetic nervous system does not follow the 2 cells, 2 synapse arrangement?
Endocrine
In the endocrine arm of the sympathetic nervous system, what structure do preganglionic neurons directly innervate?
Adrenal medulla
Where is the adrenal medulla?
In the center of the adrenal glands
What is released by the adrenal medulla when stimulated?
Epinephrine
Where does adrenal medulla release epinephrine?
Directly into blood
Where does epinephrine in blood go?
Directly to target cells
Where is 1st cell body located in the parasympathetic nervous system?
Midbrain and medulla
Which cranial nerve conveys 70% of the parasympathetic nervous system to our body?
Vagus (#10)
Which cranial nerve innervates almost all of our viscera?
Vagus (10)
What functions do the preganglionic neurons that exit through S2-S4 affect?
Pelvic viscera (bladder, anal sphincter)
What is length of preganglionic fibers of sympathetic nervous system?
Short
What is length of postganglionic fibers of sympathetic nervous system?
Long
What is neurotransmitter of 1st sympathetic synapse?
Acetylcholine
What is post synaptic receptor of 1st sympathetic synapse?
Nicotinic ACH receptors
What is neurotransmitter of 2nd sympathetic synapse?
Norepinephrine
What is post synaptic receptor (target) for 2nd neurotransmitter of sympathetic nervous system?
Alpha 1, beta 1 or beta 2 receptors
What is a term for a receptor that binds to acetylcholine?
Cholinergic
What term is used for a receptor that binds to norepinephrine?
Adrenergic
What receptor does epinephrine bind to on the target cell
B1 or B2
Where are alpha 1 receptors typically found?
Smooth muscle of the vasculature leading to internal organs (viscera)
Where are beta 1 receptors typically found?
Cardiac muscle (increases cardio acceleration)
Where are Beta 2 receptors found?
On smooth muscle of of lungs, bladder, intestines and uterus (relaxes)
Also smooth muscle of vessels leading to skeletal muscle (vasodilation)
Where are postganglionic cell bodies of parasympathetic nervous system
In scattered plexi close to or on target organ
Are preganglionic fibers of PSNS long or short?
Long
Are post ganglionic fibers of PSNS long or short?
Short
What is neurotransmitter of 1st synapse in PSNS?
Acetylcholine
What is receptor in 1st synapse of PSNS?
Nicotinic ACH receptors
What is neurotransmitter in 2nd synapse of PSNS?
Acetylcholine
What is receptor in 2nd synapse of PSNS?
Muscarinic ACH receptor
Do both SNS and PSNS target the same organs?
Yes
What is one exception where both SNS and PSNS doesn’t target the same organ?
Kidneys (SNS only)
Control of efferent division of autonomic originate within what parts of brain?
1) hypothalamus
2) brain stem
What does ANS control in hypothalamus?
1) body heat
2) water balance
3) appetite
What things are controlled by ANS in brain stem?
1) bladder
2) vascular
3) respiratory
4) cardiac
In resting condition, which has higher autonomic tone, sympathetic or parasympathetic?
Parasympathetic
What is the endocrine arm regulated by PSNS?
GI hormones that regulate digestion
What is cranial nerve 1
Olfactory (sensory)
Cranial nerve 2?
Optic (sensory)
Cranial nerve 3?
Oculomotor (motor)
Part of PSNS
Cranial 4
Trochlear (eye movement) motor
CN 5
Trigeminal
Sensory to face
Motor for chewing muscles
Largest
(sensory and motor)
CN 6
Abducens (motor)
eye movement outward
CN 7
Facial
Motor & sensory
Movement, expression, taste, tears
Parasympathetic
CN 8
Vestibulocochlear
Sensory
Balance and hearing
CN 9
Glossopharyngeal
Sensory and motor
Part of PSNS
CN 10
Vagus
Autonomic
70% of parasympathetic to body
Sensory and motor
CN 11
Accessory
Motor
SCM and traps
CN 12
Hypoglossal
Motor